A post-quantum accelerator passed its full known-answer test suite while carrying a defect that only surfaced at reject-loop iteration 5.

arXiv 2609.04058 reports deployed silicon where the standard acceptance gate structurally cannot detect a class of ML-DSA defects: signing resamples until a candidate meets its norm bounds, so the executed path varies with the message, while known-answer tests use fixed vectors and only reach the depths their seeds trigger. The accelerator carried a norm check that outran block-RAM latency, leaving each candidate's final coefficients unverified. Replacing the gate with a byte-exact golden-reference oracle plus randomized adversarial soak gave 301,343 data-dependent signings with zero escapes. This is the "you have not watched your test fail" problem in hardware (arXiv).